<?php

/**
 * Socket wrapper class used by Socket Adapter
 *
 * PHP version 5
 *
 * LICENSE
 *
 * This source file is subject to BSD 3-Clause License that is bundled
 * with this package in the file LICENSE and available at the URL
 * https://raw.github.com/pear/HTTP_Request2/trunk/docs/LICENSE
 *
 * @category  HTTP
 * @package   HTTP_Request2
 * @author    Alexey Borzov <avb@php.net>
 * @copyright 2008-2016 Alexey Borzov <avb@php.net>
 * @license   http://opensource.org/licenses/BSD-3-Clause BSD 3-Clause License
 * @link      http://pear.php.net/package/HTTP_Request2
 */
/** Exception classes for HTTP_Request2 package */
require_once 'HTTP/Request2/Exception.php';

/**
 * Socket wrapper class used by Socket Adapter
 *
 * Needed to properly handle connection errors, global timeout support and
 * similar things. Loosely based on Net_Socket used by older HTTP_Request.
 *
 * @category HTTP
 * @package  HTTP_Request2
 * @author   Alexey Borzov <avb@php.net>
 * @license  http://opensource.org/licenses/BSD-3-Clause BSD 3-Clause License
 * @version  Release: @package_version@
 * @link     http://pear.php.net/package/HTTP_Request2
 * @link     http://pear.php.net/bugs/bug.php?id=19332
 * @link     http://tools.ietf.org/html/rfc1928
 */
class HTTP_Request2_SocketWrapper {

	/**
	 * PHP warning messages raised during stream_socket_client() call
	 * @var array
	 */
	protected $connectionWarnings = array();

	/**
	 * Connected socket
	 * @var resource
	 */
	protected $socket;

	/**
	 * Sum of start time and global timeout, exception will be thrown if request continues past this time
	 * @var  integer
	 */
	protected $deadline;

	/**
	 * Global timeout value, mostly for exception messages
	 * @var integer
	 */
	protected $timeout;

	/**
	 * Class constructor, tries to establish connection
	 *
	 * @param string $address        Address for stream_socket_client() call,
	 *                               e.g. 'tcp://localhost:80'
	 * @param int    $timeout        Connection timeout (seconds)
	 * @param array  $contextOptions Context options
	 *
	 * @throws HTTP_Request2_LogicException
	 * @throws HTTP_Request2_ConnectionException
	 */
	public function __construct($address, $timeout, array $contextOptions = array()) {
		if (!empty($contextOptions) && !isset($contextOptions['socket']) && !isset($contextOptions['ssl'])
		) {
			// Backwards compatibility with 2.1.0 and 2.1.1 releases
			$contextOptions = array('ssl' => $contextOptions);
		}
		if (isset($contextOptions['ssl'])) {
			$contextOptions['ssl'] += array(
				// Using "Intermediate compatibility" cipher bundle from
				// https://wiki.mozilla.org/Security/Server_Side_TLS
				// 'ciphers' => 'AES128+EECDH:AES128+EDH:DES-CBC3-SHA:!aNULL:!eNULL'
				'ciphers' => 'ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:'
				. 'ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:'
				. 'DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:'
				. 'ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:'
				. 'ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:'
				. 'ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:'
				. 'ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:'
				. 'DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:'
				. 'DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:'
				. 'ECDHE-RSA-DES-CBC3-SHA:ECDHE-ECDSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:'
				. 'AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:'
				. 'AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:'
				. '!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA'
			);
			if (version_compare(phpversion(), '5.4.13', '>=')) {
				$contextOptions['ssl']['disable_compression'] = true;
				if (version_compare(phpversion(), '5.6', '>=')) {
					$contextOptions['ssl']['crypto_method'] = STREAM_CRYPTO_METHOD_TLSv1_1_CLIENT | STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT;
				}
			}
		}
		$context = stream_context_create();
		foreach ($contextOptions as $wrapper => $options) {
			foreach ($options as $name => $value) {
				if (!stream_context_set_option($context, $wrapper, $name, $value)) {
					throw new HTTP_Request2_LogicException(
					"Error setting '{$wrapper}' wrapper context option '{$name}'"
					);
				}
			}
		}
		set_error_handler(array($this, 'connectionWarningsHandler'));
		$this->socket = stream_socket_client(
				$address, $errno, $errstr, $timeout, STREAM_CLIENT_CONNECT, $context
		);
		restore_error_handler();
		// if we fail to bind to a specified local address (see request #19515),
		// connection still succeeds, albeit with a warning. Throw an Exception
		// with the warning text in this case as that connection is unlikely
		// to be what user wants and as Curl throws an error in similar case.
		if ($this->connectionWarnings) {
			if ($this->socket) {
				fclose($this->socket);
			}
			$error = $errstr ? $errstr : implode("\n", $this->connectionWarnings);
			throw new HTTP_Request2_ConnectionException(
			"Unable to connect to {$address}. Error: {$error}", 0, $errno
			);
		}
	}

	/**
	 * Destructor, disconnects socket
	 */
	public function __destruct() {
		fclose($this->socket);
	}

	/**
	 * Wrapper around fread(), handles global request timeout
	 *
	 * @param int $length Reads up to this number of bytes
	 *
	 * @return   string Data read from socket
	 * @throws   HTTP_Request2_MessageException     In case of timeout
	 */
	public function read($length) {
		if ($this->deadline) {
			stream_set_timeout($this->socket, max($this->deadline - time(), 1));
		}
		$data = fread($this->socket, $length);
		$this->checkTimeout();
		return $data;
	}

	/**
	 * Reads until either the end of the socket or a newline, whichever comes first
	 *
	 * Strips the trailing newline from the returned data, handles global
	 * request timeout. Method idea borrowed from Net_Socket PEAR package.
	 *
	 * @param int $bufferSize   buffer size to use for reading
	 * @param int $localTimeout timeout value to use just for this call
	 *                          (used when waiting for "100 Continue" response)
	 *
	 * @return   string Available data up to the newline (not including newline)
	 * @throws   HTTP_Request2_MessageException     In case of timeout
	 */
	public function readLine($bufferSize, $localTimeout = null) {
		$line = '';
		while (!feof($this->socket)) {
			if (null !== $localTimeout) {
				stream_set_timeout($this->socket, $localTimeout);
			} elseif ($this->deadline) {
				stream_set_timeout($this->socket, max($this->deadline - time(), 1));
			}

			$line .= @fgets($this->socket, $bufferSize);

			if (null === $localTimeout) {
				$this->checkTimeout();
			} else {
				$info = stream_get_meta_data($this->socket);
				// reset socket timeout if we don't have request timeout specified,
				// prevents further calls failing with a bogus Exception
				if (!$this->deadline) {
					$default = (int) @ini_get('default_socket_timeout');
					stream_set_timeout($this->socket, $default > 0 ? $default : PHP_INT_MAX);
				}
				if ($info['timed_out']) {
					throw new HTTP_Request2_MessageException(
					"readLine() call timed out", HTTP_Request2_Exception::TIMEOUT
					);
				}
			}
			if (substr($line, -1) == "\n") {
				return rtrim($line, "\r\n");
			}
		}
		return $line;
	}

	/**
	 * Wrapper around fwrite(), handles global request timeout
	 *
	 * @param string $data String to be written
	 *
	 * @return int
	 * @throws HTTP_Request2_MessageException
	 */
	public function write($data) {
		if ($this->deadline) {
			stream_set_timeout($this->socket, max($this->deadline - time(), 1));
		}
		$written = fwrite($this->socket, $data);
		$this->checkTimeout();
		// http://www.php.net/manual/en/function.fwrite.php#96951
		if ($written < strlen($data)) {
			throw new HTTP_Request2_MessageException('Error writing request');
		}
		return $written;
	}

	/**
	 * Tests for end-of-file on a socket
	 *
	 * @return bool
	 */
	public function eof() {
		return feof($this->socket);
	}

	/**
	 * Sets request deadline
	 *
	 * @param int $deadline Exception will be thrown if request continues
	 *                      past this time
	 * @param int $timeout  Original request timeout value, to use in
	 *                      Exception message
	 */
	public function setDeadline($deadline, $timeout) {
		$this->deadline = $deadline;
		$this->timeout = $timeout;
	}

	/**
	 * Turns on encryption on a socket
	 *
	 * @throws HTTP_Request2_ConnectionException
	 */
	public function enableCrypto() {
		if (version_compare(phpversion(), '5.6', '<')) {
			$cryptoMethod = STREAM_CRYPTO_METHOD_TLS_CLIENT;
		} else {
			$cryptoMethod = STREAM_CRYPTO_METHOD_TLSv1_1_CLIENT | STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT;
		}

		if (!stream_socket_enable_crypto($this->socket, true, $cryptoMethod)) {
			throw new HTTP_Request2_ConnectionException(
			'Failed to enable secure connection when connecting through proxy'
			);
		}
	}

	/**
	 * Throws an Exception if stream timed out
	 *
	 * @throws HTTP_Request2_MessageException
	 */
	protected function checkTimeout() {
		$info = stream_get_meta_data($this->socket);
		if ($info['timed_out'] || $this->deadline && time() > $this->deadline) {
			$reason = $this->deadline ? "after {$this->timeout} second(s)" : 'due to default_socket_timeout php.ini setting';
			throw new HTTP_Request2_MessageException(
			"Request timed out {$reason}", HTTP_Request2_Exception::TIMEOUT
			);
		}
	}

	/**
	 * Error handler to use during stream_socket_client() call
	 *
	 * One stream_socket_client() call may produce *multiple* PHP warnings
	 * (especially OpenSSL-related), we keep them in an array to later use for
	 * the message of HTTP_Request2_ConnectionException
	 *
	 * @param int    $errno  error level
	 * @param string $errstr error message
	 *
	 * @return bool
	 */
	protected function connectionWarningsHandler($errno, $errstr) {
		if ($errno & E_WARNING) {
			array_unshift($this->connectionWarnings, $errstr);
		}
		return true;
	}

}

?>
